ABB SM500F User Manual page 108

SM500F
Field mountable paperless recorder
106
Select an alarm enable source. When the 'Enable source' is active, the
alarm is enabled. When the source is inactive the alarm is disabled. If set
to 'None' the alarm is always enabled.
Note. For Delayed Process alarm operation, see Fig. 7.15, page 103.
Set 'Log enable' to 'On' to record all changes in the alarm state in the
Alarm event log – see Section 4.7, page 43.
Set 'Acknowledge Timeout' to 'On' to enable an alarm acknowledgement
timeout period that can then be set to between 1 and 999 minutes.
If the alarm is acknowledged but the alarm condition is not cleared within
the time-out period,
'active/unacknowledged'.
Note. The 'Acknowledge Timeout' function is designed to prevent an
alarm from being acknowledged but the reason for the occurrence being
ignored.
Example. An application has a vital requirement for a product to be kept
below a certain temperature (the alarm setpoint) and the recorder's alarm
relay is connected to an external audible warning device. If the
temperature exceeds the alarm setpoint, the alarm is activated, triggering
the audible warning. To preserve accountability, the alarm can be
acknowledged only by an operator with alarm acknowledgement
privileges (see Section 7.6.5, page 80) and if acknowledged, the audible
warning is silenced. If the temperature does not drop below the alarm
setpoint before the time-out period expires, the alarm state is reset to
active/unacknowledged and the audible warning sounds again.
Assign the alarm to one or more of 12 groups.
The alarm states assigned to each group are 'ORed' together to create an
internal digital signal that may be assigned to relays, digital outputs or
internal digital controls.
the acknowledge state
7 Configuration
is set back to
IM/SM500F Rev. Z